Conversion of high boiling point hydrocarbon oils into lower boiling point hydrocarbon oils



R. E. WILSON CONVERSION OF HIGH BOILING POINT HYDROCARBON 0I INTO LOWER BOILING POINT HYDROCARBON OILS Filed OCC. 18, 1926 5 Sheets-Sheet l R E. WILSON 2,921,47I oILs RBON oILs CONVERSION OF HIGH BOILING POINT HYDROC'ARBON INTO LOWER BOILING POINT HYDROCA 5 Sheets-Sheet 2 Filed Oct, 18, 1926 gv. E9, 1935. R. E. WILSON 2,02L471 CONVERSION OF HIGH BOILING POINT HYDROCARBON OILS RBON OILS INT0 LOWER BOILING POINT HYDROCA Filed Oct. 18, 1926 5 Sheets-Sheet 3" ooooooo \ooooooo oU/ooooooo Nov. i9, 1935. R. E. WILSON 2,021,471

, CONVERSION OF HIGH lROILING POINT HYDROCARBON-OILS INTO LOWER BOILING POINT HYDROCARBON OILS Filed 0st. 18, 1926 5 Sheets-Sheet, 4

1 I1' 60 47 if i Nov. 19, 1935. R. E. WILSON l 2,021,471

CONVERSION OF HIGH BOILING POINT HYDROCARBN OILS INTO LOWER BOILING POINT HYDROCARBON OILS Filed 00TH 18, 1926 5 Sheets-Sheet 5 @if @if o- 106 l i l@ a n j` am 96 i.. gm

v f/ s a' al A l Jaz 105 jzyezz' Patented Nov. 119i, 1935 if NT FFICE Robert E. Wilson, Chicago, lll., assigner to Standard Oil Company, Whiting, 1nd., a corporation of Indi Application October 18, 1926, Serial No. 142,316

37 Claims.

The present invention relates to improvements in processes for the conversion of higher boiling point hydrocarbon oils into lower boiling point hydrocarbon oils, particularly of the gasoline type, wherein the conversion is effected by heating under pressure, and will be fully understood from the following description, illustrated by the accompanying drawings, in which:

Figure 1 is a diagrammatic view of apparatus suitable for carrying the invention into eiiect and showing insulation and also condenser.V box in section;

Fig. 2 is a vertical sectional view through an expansion and reaction chamber as employed in accordance withy the present invention;

Fig. 3 is a horizontal sectional view on the line l'3 of Fig. 2;

Fig. 4 is a horizontal sectional view through the expansion and reaction chamber on the line t, of Fig. 2; l

Fig. 5 is a vertical sectional view through the tower receiving the vapors and unvaporized liquid from the expansion and reaction chamber;

Fig. 6 is a transverse sectional view through the tower of Fig. 5, on line 6;

Fig.-'7 is a transverse sectional view through the tower of Fig. 5 on the line l;

Fig. 8 is a transverse sectional view through the tower of Fig. 5 on the line 8;

Fig. 9 is a vertical' sectional view of a receiving chamber or drum which receives condensates selected from various points in the column of Fig. 5;

Fig. 10 is a vertical sectional view through a vapor fractionating and stripping column;

Fig. 1l is a sectional view illustrating diagrammatically a water separating device; and

Fig. l2 is a vertical sectional view illustrating diagrammatically a device for separating gas from condensate.

Referring more particularly to the drawings, the numeral 20 indicates a furnace setting in which is mounted a pipe coil 2| through which the oil to be converted is passed under suitable conditions of pressure and temperature, as hereinafter more fully set forth, to bring it to the desired conversion conditions. The furnace and pipe coils may be constructed in any suitable manner, excessive local heating beingy avoided, and are adapted to be employed at high tem peratures and pressures. A suitable method of constructing and operating the pipe still and setting is shown in my co-pending application Serial No. 145,515, filed November 1, 1926.

Pipe coils 2| in the setting 26 receive the stock fed them from pipe 22 through the inlet pipe 23, and after it is brought to the desired temperature conditions, and the latter has been maintained for a suitable length of time, the heated oil is discharged from the pipe still through the 5 outlet pipe 2t. If desired, more or less of the cooler feed stock may be supplied from the pipe 22 through the valved pipe 25 to the heated oil in the outlet pipe 2t immediately upon its discharge from the pipe still. The heated oil then 10 passes through a pressure reducing valve 26 and enters one or more valved nozzles 2l, or nozzle valves as in my co-pending application Serial No. 112,024, led May 27, 1926, by which it is introduced into the enlarged chamber or still 28, preferably tangentially in the lower portion thereof. This chamber is suitably constructed of heavy walled material to stand high pressures, although the pressures prevailing therein are not ordinarily as high as those maintained in the -pipe coils 2|, and is preferably lagged. The enlarged chamber 28 is ordinarily unheated, the temperature attained by the oil in the coils 2| being such that a conversion temperature at which a rapid rate of conversion is attained, is maintained in the chamber 28. The nozzles 2l by means of which the heated oil is introduced into the chamber 28 are preferably tangentially disposed, and the agitation produced by the tangential introduction of the heated oil inthe lower 30 portion of the chamber aids in minimizing any settling of tarry or coke sediment in the chamber 28. An approximately constant level of liquid is maintained in the chamber 28, a level indicator 29 operated by iioat 30 being provided for its 35 observation. `Vapore separating from the liquid in the chamber 28 pass out through the vapor line 3| and enter, preferably tangentially, the

' lower portion of a lagged column 32, shown in sectional view in Figs. 5 to 8 inclusive. The un- 40 vaporized liquid or residue from the chamber 28 is drawn cut substantially continuously through a pipe 33 protected by a baille 34, (see Fig. 2) and enters the tower 32, likewise tangentially, at a point somewhat higher than the point of entrance of the vapors through line 3|. Between the point of entrance of the vapor line 3| and that of the unvaporized liquid line or tar line 33 in the column 32 there are provided a number of suitable iractionating plates 35, adapted to tolcrate considerable coke without clogging, suitably of doughnut and disk type.

At an intermediate point in the ,column 32, above the point of entrance of the line 33 for unvaporlzed liquid, there is provided a cut-ofi or trap-out plate 36 provided with a central cylindrical conduit or pipe 31 which permits free passage of vapors upwardly from the lower portion of the column 32. Through this cylindrical vapor pipe 31 the vapors enter a compartment of the tower separated from the upper portion of the tower by a partition 38. A pipe coil 39 is provided in the column around the vapor line 31, and vapors rising through the latter pass downwardly through the annular space surrounding it, passing around the pipe coils 39. Uncondensed vapors enter the external vapor pipes 40 by which they are led back into the column 32 at a point just above the partition 38. The vapors then rise through a. plurality of fractionating plates `4I, of which the lowermost is indicated as 4|. Reux condensate formed in this part of the tower flows downwardly to the lowermost plate 4|. This plate, in the form illustrated, is provided with overflow pipes 42, which discharge into the small collecting chambers 43 connected by pipe 44. From one of these chambers 43, the condensate may be withdrawn through the line 45.

vCondensate formed in the compartment between the plate 36 of the column and the partition 38 collects in the annular chamber surrounding the vapor pipe 31 and is withdrawn through the overflow pipe 46 and conduit 41. Below the plate 36 and above the point of entrance of the line 33 there are provided a number of fractionating plates 48, suitably of the bubble-cap type. Between two of these plates, means such as the conduit 49 are provided for the supply of a suitable oil to the column, as hereinafter more fully described. This oil may be, for example, a reduced crude oil.

In order to aid condensation and reflux formation in the upper part of the column 32, a suitable hydrocarbon oil, for example, of the kerosene range of boiling points, may be introduced above the plates 4|, for example, through the conduit 58. Vapors uncondensed in the upper portion of the column 32 pass out through the vapor line 5|. The column 32 is preferably operated at slightly above atmospheric pressure or at any suitable pressure below the pressure prevailing in the chamber 28, and lines 3| and 33 leading from the latter are suitably provided with suitable pressure reducing valves 52 and 53 respectively.

The oil removed from the column 32 through the line 45 enters the upper compartment of a two-compartment drum 54. The compartments are formed in this chamber by a partition 55 provided at its lowest point with an outlet pipe 58 leading to the conduit 51. Both the upper and the lower compartments of the chamber 54 are provided with level indicators 58 operated by floats 59. Liquid oil withdrawn from the column 32 through the line 41 enters the lower compartment of the drum 54, which is provided with a valved outlet pipe 60 at an intermediate point, this pipe connecting with the conduit 51.

The lower compartment of the drum 54 is likewise provided with a cond valved discharge pipe 8| leaving near the bottom of the compartment. The conduits 51 and 8| are connected by a valved connection 62. A valve 63 is provided in the line 51 before this connection 62 is reached. From the point at which the connection 62 joins the line 6|, a valved line 64 leads to a pump 65. From the point where the connection 82 joins the line 51, a valved suction line 68 leads to the pump 61. The pumps 65 and 61 discharge through valved lines 88 and 69 respectively into the line 22 leading to the pipe still 2|. Each of the pumps is likewise provided with a valved discharge connection 18 so that, if desired, the oil discharged by either pump may be forced to storage. By the connections just described, the pumps 55 and 61 can be made to handle separately the oil from the lower and upper compartments respectively of the drum 54; or either pump can be made to handle the combined oil from both compartments of the drum 54 or any desired proportions thereof. Pumps 65 and 61 are positioned below drum 54.

The vapors pass out of the column 32 through the vapor line 5|, to column 1|, illustrated in section in Fig. 10. The unvaporized liquid or tar from the bottom of the column 32 is discharged through the line 12 and passes through the heat exchanger 13, in which there is a heat exchange between the tar and oil supplied through pipe |25, as hereinafter set forth. The

tar is then discharged from the heat exchanger through the pipe 15 to a suitable tar cooler 11, from which it passes out through line 18 to a tar pump 19, which discharges from the systeml through the line 80.

As hereinbefore stated, t-he vapors from the column 32 enter the fractional condensing column' 1I at an intermediate point. Above the point of entrance of these vapors, there are provided a number of suitable fractionating plates, for example bubble plates 8| and below the point of entrance of the vapors, there are likewise provided a plurality of plates, suitably bubble plates 82. Any suitable means for supplying a cooling agent in the upper part of the column may be provided; for example, a cooling oil of the character hereinafter set forth may be supplied in the upper portion of the column through the pipe 83. Condensate formed in the column descends to the lower port-ion thereof and preferably a body of such condensate is maintained therein, suitable means, such as the oat oper-'- ated indicater 84 being provided for observing its level. If desired, steam may be supplied in the lower portion of the column 1|, preferably below the surface of the condensate collected therein, for example, through the steam line 85 terminating in the perforated coil 86 in the lower p rtion of the column. The stripped condensate from the column is discharged through the valved line 81 and ows into a receiver 88, from which it is discharged by means of a pump 89. The. discharge line 99 of the pump 89 is provided with a valved connection 9| leading to storage and with a second valved connection 92 connecting with the line 50 leading into the upper portion of the column 32, as already set forth. It is obvious that by means of these connections, controlled proportions of the condensate collected in the receiver 88 may be returned to the upper portion of the column 32 and employed as a cooling medium therein.

Uncondensed vapors passing out of the column 1| through the vapor line 93 enter the condenser 94 and the condensate and cooled gas pass there'- from throughline 95 to a separator-96 of any suitable construction. A form' of construction which may be employed for this separator is illustrated diagrammatically in section in Fig. l2. The condensate and gas enter through the line 95 in the lower portion of the separator 96, and above the point of entrance a. plurality of suitable plates, such as the bubble plates 91 are provided.

Within the separator 96 separation of liquid and 75 2,021,471 gas takes place, entrained liquid being separated from the gas by the action of the plates9l, aided by cold water or other suitable liquid supplied in the upper portion of the separator above the plates 91 through the valve-controlled line 98. The separated gas passes out through the line 99 provided with a control valve |00. The condensate, together with the water added pass out from the bottom of the separator through the line |0|, which extends to the bottom of a trap |02, likewise illustrated diagrammatically in section in Fig. 12. The condensate and water pass out of the trap through the line |03 into a separator |04, illustrated diagrammatically in section in Fig. 11. As shown in Fig. 11 the pipe |03 enters the separator |04, bending downwardly and opening at an intermediate point therein. Water separates from the condensate in the sep'arator |00, and is withdrawnthrough the outlet pipe |05 which extends downwardly within the separato;` to the lower portion thereof. The separated light oil condensate overows through the line |06 to the look box |01, from which discharge line |08 leads to the receiver |09. The separator |04, look box |01 and receiver |09 are provided with gas vents ||0, ll and H2 respectively, which connect with a manifold H3 leading into a vent pipe, H0 from the line |03 to an intermediate point in the gas Separator 95, preferably below the uppermost plate 97.

'Ihe light condensate in the receiver |09 passes out through the line ||5 to the pump H6, the discharge line l from which is provided a valve connection ||8v leading to storage. A second valve connection I9 is provided'from the discharge line and leading into the pipe 03 by which this condensate may be supplied tothe upper portion of the column ll, as already described.

Oil is supplied for use in the system through the line |20 leading to the pump I2|, by which it is forced through line |22, entering the coils 39, in which it is pre-heated by the vapors in the column. The oil leaving the coils 39 passes out through the pipe |23 to a vapor separator |20. From the vapor separator |24, a liquid discharge line |25 leads to an end compartment of the exchanger 13. The oil passes through tubes in the exchanger and leaves from the opposite end through the pipe 49 by which it is introduced into the tower 32 at an intermediate point below the` partition 36.

In order that the invention may be fully understood, it will be described in connection with the treatment of a mid-continent' oil, for example, a mid-continent crude or crude residuum. The crude oil from storage is supplied by line |20 to pump |2| by which it is forced through line |22 into and through the coils 39, in which it is-heated to a temperature which is substantially below that at which appreciable cracking takes place (say, 350 to 450 F) by the vapors from the lower portion of the tower 32, the nature of said vapors being more fully hereinafter'pointed out. The partially heated oil passes out of the coils 39 through the pipe |23 into the vapor separator |20. At the temperature of exit from the coil 3S, a substantial amount of vaporization takes place. Vapors formed are released in separator |24 and pass out through line |258 into one 0f the vapor lines 40 leading into the upper part of column 32. The liquid or oil from which the lighter vapors have been released passes out of the separator |24 through the line |25 and enters the heat exchanger 13, passing through the tubes therein, the external surfaces of these being contacted with the residual oil from the base of the tower 32. There is some further heating of the oil in its passage through the tubes of the heat exchanger, and it makes its exit therefrom at a 5 temperature of 450 to 500 F. or thereabout.

The heated reduced crude oil then passes through the line 49 into the lower compartment of the tower 32 above at least some of the circulating or bubble plates 48 therein. The lower 10 compartment of the tower also receives converted oil products at a high temperature, as hereinafter more fully set forth, so that a substantial portion of the crude oil introduced through Vthe line 49 is vaporized by the heat of the converted oil prod- I5 ucts; i. e., the products derived from the conversion system. The vapors from this oil, together with vapors from the converted products also supplied to the lower compartment of the tower, pass upwardly through the conduit 3l in 20 the partition 36, the temperature of these vapors being suitably in theneighborhoodof 600 to 700 F. and preferably about 650 F. These vapors, after leaving the conduit 31, pass downwardly through the annular space surrounding it, and in doing 20 so contact with the outer surfaces of the coils 39, through which, as hereinbefore set forth, the crude oil is caused to pass. In the preferred form of construction, as illustrated, `the vapors travel in countercurrent to the general direction of movement of the crude oil passing through the coils 39. The vapors then pass out through the vapor lines 40 to the upper portion of the tower. I'he operation of the tower will be more fully de scribed hereinafter. The condensate from the as vapors formed by the cooling action of the oil passing through the coils 39 collects in the tower on the partition 36 andis drawn oi through the line 4l to the lower compartment of drum 54 in which a body thereof is maintained, its level 4,0 being indicated by the indicator 58 controlled by float 59. A lighter reux condensate is drawn off from the tower 32 through the line 45 and this ows into the upper compartment of the drum 54, in which a body of this lighter condensate stock g5 is maintained, its level being observed by means of the oat indicator 58. The stock may be drawn oi from the lower compartment of the container 54 through the pipe 6| or through the pipes 60 and 51. The lighter reflux condensate 5o stock collected in the upper compartment of the drum 54 may be drawn off through the pipes 56 and 51. The stocks collected in the compartments of drum 54 are each substantially at its boiling point and either stock may consequently 55 be handled at a maximum temperature and with a minimum loss of heat. By suitable connections, which have already been fully described, the oil from either compartment of the drum 54,

@or mixtures thereof, in any desired proportions @0 may be picked up by either or both of the pumps 65 and 61 and forced through the lines 68 and 69 respectively into the feed line 22 by which the oil to be converted is fed to the conversion furnace 20. These pumps put the oil under high 65 pressure, suitably a pressure of 900 tol200 lbs., although if desired pressures from 500 lbs. upwards may be employed.

The feed stock, under pressure, is forced through the pipe coils 2| in the furnace 20 in 70 which it is brought to conversion temperature and preferably under such conditions that a very substantial conversion is eiected (say from 10 to 25% and preferably above 13%) into desired low boiling point products in the gasoline boiling 75 point range at the time the oil emerges from the coil through the outlet pipe 24. The velocity of flow is maintained at such a rate that substantially no deposition of coke takes place within the pipe still 2 I. The oil is discharged therefrom vat a suitable temperature in excess of 780 F., and

preferably at a temperature of 850 to 950 F., the pressure at the outlet of the coil being suitably 900 to 1100 lbs.

The heated oil then passes through pressure release valve 26 and through the tangential discharge nozzles 21 provided with pressure release valves and enters near the bottom of the enlarged chamber 28 which is preferably insulated so that a conversion temperature is maintained therein. The pressure maintained in the chamber 28 is also very high, (above 100 lbs. per square inch), although preferably not above '150 lbs. per square inch. For example, a pressure of 250 to 750 lbs. per square inch or preferably about 500 lbs. may be maintained therein. The temperature of the material in the interior of the chamber 28 is maintained at from 140 to 860 F., for example, about 800 F. In order to aid in securing the desired temperature in the chamber 28, feed stock may be diverted from the main feed line 2| through the valved line 25 to the outlet pipe 24 from the pipe still 2|. A controlled amount of the cooler feed stock may be supplied through this line to the heated feed stock emerging from the coil. Inthis way any desired control of the temperature within the chamber 28 below the temperature at the outlet of the pipe coil may be secured.

In the still 28 a separation of vapors from unvaporized oil takes place. The unvaporized oil, drawn off from a point near the surface of the liquid body in the still through the line 33, enters the column 32 after passing through the discharge valve 53 by which it is reduced to a substantially lower pressure, preferably only slightly above atmospheric; for example, 2 to 5 lbs. This unvaporized oil enters the lower compartment of the column 32 at an intermediate point below the fractionating plates 48 and above the fractionating plates 35. As a result of the reduction of pressure, there is a substantial cooling of the material discharged from the outlet pipe 33, and there is also a substantial vaporization of the oil. Under the conditions herein described, the products will be discharged from the line 33 at a temperature of 700 to 750 F. The vapors from the still 28 pass out through the line 3| and enter the column 32 in the lower portion thereof, below the plates 35 and below the point of entrance of the line 33 carrying products unvaporized in the st -ll 28. A pressure release valve 52 is provided in the vapor line 3|, and is so controlled that the vapors from the still 28 enter the column 32 at a pressure equal to or only slightly more than the pressure at which the products passing through the line 33 enter the column 32. In general the vapors enter the column 32 at a somewhat higher temperature than the products issuing from the line 33. Both the lines 3| and 33 may be caused tc enter the column 32 tangentially, as indicated clearly in section in Fig. 8.

The vapors released from the products unvaporized in the still 28 and discharged through the line 33 rise in the column 32 and pass through the bubble plates 48 in the customary manner. The unvaporized liquid or tar descends the column and, by the action of the fractionating lates 35 is brought into intimate contact with e ascending vapors brought in through the line 3|. 'I'hese vapors strip the lighter constituents of the liquid, and in this action they are assisted by the fact that they are at a somewhat higher temperature than the liquid itself. At the same time, if desired, steam may be introduced into the column through the line |21. The vapors derived from the converted products rise through the lower portion of the column and pass upwardly through the conduit 31. As has already been pointed out, crude or reduced crude oil, or other feed oil, which has been preheated by vapors in the tower 32, is introduced into the lower portion of the column above the lower of the fractionating plates 48 by means of the line 49. A substantial portion of this oil is vaporized by the heat of the products derived from the still 28 and the pipe still 2|, and these vapors pass upwardly through the conduit 31 with the vapors from the converted products. The combined vapors then pass downwardly through the annular chamber surrounding the conduit 31 and containing the coil 39 through which the crude oil entering the system is passed for preheating.

There is a substantial cooling of the vapors by the cooler oil with the result that a condensate is formed which collects in the annular chamber above the partition 36. The approximate temperature at this point may be, under normal conditions of operation, about 500 to 600 F. The temperature is pareferably maintained sufciently high to cause all of the gasoline fractions and most or all of the kerosene fractions remain in vapor state. The condensate formed is drawn off through the overflow pipe 46 and the line 41 to the drum 54 `to form a part of the feed stock for the pipe still, as hereinbefore described, and consists of vaporized and subsequently condensed portions from both the crude oil and the conversion products from the system. The vapors pass through the vapor pipes 4|) to the upper portion of the column above the partition 38 and rise through the bubble plates 4|8- and 4|. Suitable cooling means may be employed in this portion of the tower; for example, a condensate fraction of the nature of kerosene may be pumped into the upper portion of the column through the line 50. Substantially all of the oil so introduced is vaporized and passes out through the vapor line 5| with the uncondensed vapors. The condensed products reux to the lower plate, from which the overflow pipes 42 lead to the chambers 43 which are interconnected by pipe 44 and from which reflux condensate is drawn off through the line 45 to the upper compartment of the drum 54. This reflux condensate which contains both unconverted products directly derived from crude oil or reduced crude oil introduced into the lower portion of -the tower 32 and converted products derived from the pressure heating system is of -lighter character than the condensate drawn oi through the line 41. The temperature conditions within the upper portion of the column are preferably so maintained. that substantially no products of the gasoline range boiling point are retained within the condensate formed and drawn off through the pipe 45, these being largely in the gas oil and/or kerosene range of boiling points. The products of the gasoline together with more or less in the kerosene range of the boiling points pass off through the vapor conduit 5| and enter the fractionating and stripping co1- umn 1| at an intermediate point. The vapors rise through the fractionating plates 8| above their point of admission in the column 1|. Suitable cooling means should be provided in the upper portion of the column. A suitable cooling oil, for example, of the nature of the final condensate, may be supplied above the uppermost plate through the line 83. Reiiux formed in the column descends to the lower portion thereof, passing downwardly through the stripping plates 82 and collecting in the bottom of the column, the level of the collected condensate being indicated by the level indicator 84.' A suitable inert gas or other stripping medium, such as steam may be supplied in the lower portion of the column, for example, through the -line 85 and the perforated distributing pipe 86. The steam and vapors pass upwardly through the column and aid in stripping the reflux of its lighter ends. As a result of the action of the column '|I, which may be Asuitably controlled, vapors of the desired low boiling end products such as those of the gasoline boiling point range, pass out through the vapor line 93, together with such steam as may be used in the column. The heavier boiling point products, for example, of the kerosene boiling point range, or the heavier portion of the gasoline form the reflux condensate collected in the bottom of the column and passes out at a controlled rate of discharge through the line 81 to the receiver 88. From the receiver, it may be picked up by pump 89 and discharged through the line 90, which is provided with two valve connections one, designated by the numeral 9 I, leading to storage and the other, designated 92, leading to the line 50 so that "any predetermined quantity of these hydrocarbons may be supplied to the upper portion of the uppermost compartment of the column 32 in order to produce the desired cooling action therein, as hereinbefore described. The vapors of the low boiling point products, together with steam pass out of the column II through the line 93 and enter the condenser 94, passing through the coil therein, the

condensed and cooled products dischargingf through the line 95 into the separator 96, shown in Fig. l2. This separator contains plates, suitably of the bubble cap type. The condensed and cooled products enter in the lower portion of the drum or separator S6. The condensed portions are separated and discharged through the line IUI. Gas passes out, ascending through the plate 9'.' and preferably washed by a hydrocarbon fraction, suitably of the gasoline range of boiling points, supplied through the line 98. 'Ihe washed gases then pass out through the line 99, preferably to a suitable absorption system for removing therefrom their gasoline constituents.

The separated condensate discharged through the line |0| passes through the trap |02 and out through the line |03 to the water separating device |04, shown in section in Fig. 11. Separation of water takes place `in this device, and the separated water is discharged from the lower portion of the tank through the line |05, while the light oil or gasoline passes out through the line |06 and the look box |01 to the receiving chamber |09. The line |03, the separator |04, the lock box |01 and the receiver |09 are provided with vents which discharge through the line I I4 into the gas separating drum 96, preferably below the uppermost plate therein.

The gasoline condensate collected in the receiver |09 is picked up through the line ||5 by the pump H6 and discharged through the line Ill. The latter is provided with a valved connection H8 leading to storage and with a-second valved connection ||9 leading to the line 83 by which controlled quantities of the gasoline distillate may be supplied to the upper portion. of the column II as a cooling medium therein. l

` 'I'he operation of the process and apparatus of this invention has been described in connection with the utilization of a crude or reduced crude 5 oil as the initial material. 'I'he material fed to the pipe still 2| is preferably a distillate or over'- head stock, and in the. embodiment above set forth, is a mixed stock, partly virgin and partly cycle; that is, part of it is derived from the distillation of a crude oil while the remainder is derivedfrom an oil which has already been through the conversion system. The heavier condensate fractions drawn on from the tower 32 through the line 41 may be employed alone; or the lighter condensate fractions of the nature of burning oil, drawn oif through the line 45 may be employed, or mixtures of the two may be used as desired. If, however, it is regarded as preferable not to employ a crude or reduced crude oil in the process nor to utilize the superfluous heat of the products of conversion to eifect its distillation, a suitable overhead or distillate oil such as gas oil, burning oil, heavy naphtha or the like may be preheated in the same manner as the crude oil in the process as hereinbefore set forth and then fed into the column 32 above the plate 36 to be drawn oif together with reux condensate through the line 41 as feed stock.

I claim:

1. 'I'he method of converting hydrocarbon oils into lighter hydrocarbon oils of the gasoline range boiling points which comprises passing the oil to be converted through a conned passageway while heating the latter to bring the oil to 35 a conversion temperature in excess of 800 F. and maintaining thereupon a pressure inexcess of 750 lbs. per square inch, discharging the oil into an enlarged chamber maintained under a pressure materially below that prevailing in the 40 confined passage and in excess of 100 lbs. per square inch while maintaining in said chamber a conversion temperature not above that of the heated oil discharged from the coil, separately removing vapors and unvaporized oil from said chamber, separately reducing the pressure upon the removed vapors and unvaporized products whereby.` the latter are reduced to a temperature below that of the vapors, discharging the said products unvaporized in said chamber into another chamber maintained under a materially reduced pressure passed downwardly therethrough and discharging the products vaporized in said enlarged chamber into said reduced pressure chamber below the point of admission of said unvaporized products to pass upwardly therethrough countercurrent to the said unvaporized products.

2. The method of converting hydrocarbon oils into lighter hydrocarbon oils of the gasoline range of boiling points which comprises passing-v the oil to be converted in a continuous stream through a confined passageway while heating the latter to bring the oil to a conversion temperature in excess of 800 F., maintaining thereupon a pressure in excess of 750 lbs. per square inch discharging the oil into an enlarged chamber at a pressure materially below that prevailing in the confined passage and in excess of 100 lbs. per square inch while maintaining`in said chamber a conversion temperature not above that of the heated oil discharged from the coil,separately removing vapors and unvaporized oil from said chamber, separately discharging the conversion products into another chamber maintained 75 under a materially reduced pressure whereby the unvaporized products are cooled to a temperature below that of the vaporized products, contacting the removed vapors with the unvaporized portion of the conversion products in countercurrent flow within said reduced pressure chamber and separating vapors and unvaporized products within said chamber.

3. The method of converting hydrocarbon oils into lighter oils of the gasoline range of boiling points which comprises passing the oil to be converted in a continuous stream through a coniined passageway while heating the latter to bring the oil to a conversion temperature in excess of 800 F., maintaining thereupon a pressure in excess `of '150 lbs. per square inch, discharging the oil into an enlarged chamber at a pressure materially below that prevailing in the confined passage and in excess of 60 lbs. per square inch while maintaining in said chamber a conversion temperature not above that of the heated oil discharged from the coil, separately removing vapors and unvaporized voil from said chamber,

separately discharging the conversion products into another chamber maintained under a materially reduced pressure whereby the unvaporized products are cooled to a temperature below that of the vaporized products, contacting the removed vapors with the unvaporized portion of the conversion products in countercurrent ow within the reduced pressure chamber, separating vapors and unvaporized products within said chamber, subjecting the vapors in said chamber to cooling, thereby partially condensing the sam-J, withdrawing the resulting condensate, and forcing it into the continuous stream of oil owing through the heated conflned passageway.

4. The method of converting hydrocarbon oils into lighter hydrocarbon oils of the gasoline range of boiling points which comprises passing the oil to be converted in a continuous stream through a conned passageway while heating the latter to bring the oil to a conversion temperature in excess of 800V F., maintaining thereupon a pressure in excess of 750 lbs. per square inch, discharging the oil into an enlarged chamber at a pressure materially below that prevailing in the confined passage and in excess of lbs. per square inch while maintaining in said chamber a conversion temperature not above that of the heated oil discharged from the coil, separately removing vapors and unvaporized oil from said chamber, separately discharging the conversion products into another chamber maintained under a materially reduced pressure, whereby the unvaporized products are cooled to a temperature below that of the vaporized products, contacting the removed vapors with the unvaporized portion of the conversion products in countercurrent ilow within the reduced pressure chamber, separating vapors and unvaporized oil within said chamber, subjecting the separated vapors within the reduced pressure chamber to the cooling action of fresh oil to be converted, thereby forming reflux condensate and preheating the oil to be converted, and forcing the preheated fresh oil and reux condensate into the heated conned passageway.

5. In apparatus for eiecting conversion of high boiling hydrocarbon oils into lower boiling hydrocarbon oils such as gasoline, means for maintaining a body of oil at conversion temperature and pressure, means for separately withdrawing vapors and unvaporized products from said body of oil, a baiiled chamber, means for introducing the withdrawn unvaporized products into the battled chamber at an intermediate point therein and at reduced pressure, means for introducing the withdrawn vapors from the body of oil at reduced pressure into the bailled chamber below the point of entrance of the unvaporized products, whereby such vapors pass upwardly in countercurrent to the unvaporized oil products, means for introducing crude oil into the batiied chamber at an intermediate point above and close to the point of admission of the unvaporized products from the body of oil undergoing conversion, whereby the rising vapors in the baiiled chamber vaporize portions of said crude oil, means for subjecting the mingled vapors in the upper portion of the baiiled chamber to cooling action, thereby forming reflux condensate, means for withdrawing said reflux condensate, and means for heating it to conversion tempera- CII ture under pressure higher than that of the body 20 of oil maintained at conversion temperature and pressure and discharging it into the latter with reduction of pressure.

6. The method of converting hydrocarbon oils into lighter hydrocarbon oils of the gasoline 25 range boiling points which comprises passing oil to be converted in a continuous stream through a conned passageway while heating the latter to bring the oil to a conversion temperature and maintaining thereon superatmospheric pressure 30 ducing the pressure on the mixed oil products 35 and discharging them into an enlarged chamber at a materially reduced superatmospheric pressure while maintaining a conversion temperature therein, separately removing vapors and unvaporized oil from said chamber, and separately discharging them into another chamber maintained under a materially lower pressure in which the vapors enter at a point below that of entry of the unvaporized oil, the latter being cooled to a lower temperature than said vapors by the reduction in pressure and contacting the separately removed vapors with the unvaporized portion of the conversion products by countercurrent ow in said last mentioned chamber.

l, 7. The method of converting hydrocarbon oils into lighter hydrocarbon oils o the gasoline range of boiling points which comprises passing oil to be converted in a continuous stream through a confined passageway while heating the latter to bring the oil to a conversion temperature and maintaining thereon a high superatmospheric pressure suiliclent to maintain a substantial portion of the oil in the so-called liquid phase, reducing the pressure on the heated oil and discharging it into an enlarged chamber maintained under a materially lower superatmospheric pressure whereby a desired vaporization is secured in said enlarged chamber, and maintaining conversion temperature therein, separately removing vapors and unvaporized oil from said chamber, separately reducing the pressure upon said Vapors and unvaporized oil whereby the latter is cooled to a lower temperature than are the vapors, and discharging the said vapors and unvaporized oil at materially reduced pressure into another chamber at separated points, the vapors below the unvaporized oil and causing them to pass in countercurrent ow through said chamber to effect a further heating of unvaporized oil 75 products and removal of light products therefrom. v

8. The method of effecting the conversion of hydrocarbon oils into lower boiling hydrocarbon oils which comprises heating the oil to be converted under superatmospheric pressure to a conversion temperature and separating it into a vaporized portion and an unvaporized portion while under superatmospheric pressure, separately reducing the pressure upon said vaporized and unvaporized portions, whereby the latter are reduced to a temperature below that of the vapors,

admixing the resulting unvaporized portions with fresh oil and contacting them with said vaporized portions in countercurrent flow, whereby the mixture is heated and constituents thereof vaporized, separately withdrawing the remaining unvaporized residues, subjecting the resulting vapors to partial condensation and passing selected portions of the resulting condensate to the conversion stage as the charging stock therefor.

'9. The method of converting hydrocarbon oils into lower boiling hydrocarbon oils which comprises passing the oil to be converted in a continuous stream through a conned passageway while heating .the latter to bring the oil to a conversion temperature and maintaining thereon superatmospheric pressure, reducing the pressure on the heated oil and discharging it into a-n enlarged chamber maintained under a materially reduced superatmospheric pressure to secure a` desired vaporization therein while maintaining a conversion temperature in said chamber, separately removing vapors and'unvaporized oil from said chamber and materially reducing the pressure thereon whereby the unvaporized oil is brought to a lower temperature than the vapors, discharging the unvaporized oil into another chamber, admitting fresh oil to the said other chamber at a point close to the admission point of the said unvaporized oil and admixing the latter therewith, introducing said vapors separately at a lower point in said chamber and causing them to pass upwardly through said chamber countercurrent to the mixture of vaporized oil and fresh oil constituents whereby said mixture is heated and lower boilingV constituents thereof removed as vapors.

10. The method of converting hydrocarbon oils into lower boiling hydrocarbon oils which coinprises passing the oil to be converted in a continuous stream through a confined passageway while heating the latter to bring the oil to a conversion temperature and maintaining thereon superatmospheric pressure, reducing the pressure on the heated oil and discharging it into an enlarged chamber maintained under a materially reduced superatmospheric pressure to secure a desired vaporization therein while maintaining a conversion temperature in said chamber, separately removing vapors and unvaporized oil from said chamber and materiallylreducing the pressure thereon whereby the unvaporized oil is brought to a lower temperature than the vapors, discharging the unvaporized oil into another chamber and admixing it therein with fresh oil constituents, introducing said vapors separately at a lower point in said chamber and causing them to pass upwardly through said chamber countercurrent to the mixture of vaporized oil and fresh oil constituents whereby said mixture is heated and lower boiling constituents thereof removed as vapors, separately withdrawing the remaining unvaporized residues, subjecting the said removed vapors to a partial condensation operation and passing'at least a portion of the resulting condensate to the said conversion stage as the charging stock therefor.

11. The method of converting relatively high boiling hydrocarbon oils into lower boiling products which comprises owing a stream of condensate stock formed in the operation through a conned passageway while heating the latter to bring the oil stream to a conversion temperature in excess of 800 F. and maintaining thereupon a pressure in excess of '150 lbs. per sq. inch, discharging the stream into 'an enlarged chamber maintained under a pressure materially below that prevailing in the confined passage and in excess of 100 lbs. per sq. inch, maintaining in said chamber a conversion temperature not above that of the heated oil discharged from said passageway, separately removing vapors and unvaporized oil from said chamber and discharging said products into another chamber maintained under a materially reduced pressure whereby the unvaporized oil is reduced in temperature, ntroducing fresh oil into the said ,last-named chamber and admixing it with the said unvaporized oil, intimately contacting the unvaporized oil and fresh oil mixture with the said vapors in said chamber whereby the mixture is distilled, separately collecting the remaining unvaporized portion of said unvaporized oil and fresh oil mixture, separately withdrawing the vapors from said chamber including vapors of said fresh oil, partially condensing said vapors and passing at least a portion of the resulting condensate to said confined passageway to constitute the charging stoclrtherefor.

12. The method of converting relatively high boiling hydrocarbon oils into lower boiling products which comprises heating a condensate stock Vformed in the operation to a conversion temperature while maintaining it under a substantial superatmospheric pressure and separating it in to a vaporized portion and anfunvaporized portion while under superatmospheric pressure, separately reducing the pressure upon said vaporized and unvaporized portions, admixing the' said resulting unvaporized portions with fresh oil and contacting the mixture with said vaporized portions in countercurrent flow whereby the said mixture is heated and constituents thereof are vaporized,

separately collecting the remaining unvaporized portion of said mixture, separately withdrawing the vapors and subjecting them to a condensation operation, and passing at least a portion lof the resulting condensate to said conversion stage to constitute the aforesaid charging stock therefor.

13. The method of converting relatively high boiling hydrocarbon oils into lower boiling products which comprises heating a condensate stock formed in the operation to a conversion operation while maintaining it under a substantial superatmospheric pressure and separating it into a vaporized portion and an unvaporized portion while under superatmospheric pressure, separately reducing the pressure upon said vaporized and unvaporized portions, whereby the latter are reduced to a temperature below that of the vapors, admixingthe said resulting unvaporized portions with fresh oil and contacting the mixture lwith said vaporized portion in eountercurrent flow whereby the said mixture is heated and constituents thereof are vaporized, separately collecting the remaining unvaporized portion offsaid mixture, separately withdrawing the vapors and subjecting them to a partial condensation operation and passing at least a portion of the resulting condensate to said conversion stage to constitute the aforesaid charging stock therefor.

14. The method of converting relatively high boiling hydrocarbon oils into lower boiling products which comprises flowing a stream of condensate stock formed in the operation through a conned passageway while heating the latter to bring the oil stream to a conversion temperature and maintaining thereon a superatmospheric pressure, reducing thepressure on the heated oil and discharging it into an enlarged chamber maintained under a materially reduced superatmospheric pressure to secure a desired vaporization therein while maintaining a conversion temperature in said chamber, separately removing vapors and unvaporized oil from said chamber and discharging said products into another chamber maintained under a materially reduced pressure whereby the unvaporized oil is reduced in temperature, introducing fresh oil into the said last-named chamber and admixing it with the said unvaporized oil, intimately contacting the unvaporized oil and fresh oil mixture with the said vapors in said chamber whereby the mixture is distilled, separately collecting the remaining unvaporized portion of said unvaporized oil and fresh oil mixture, separately withdrawing the vapors from said chamber, including vapors of said fresh oil, partially condensing said vapors and passing at least a portion of the resulting condensate to said confined passageway to constitute the aforesaid charging stock therefor.

15. In processes for treating high boiling point hydrocarbons to produce low boiling point products therefrom, in which the high boiling point hydrocarbons are subjected to pressure distillation in a pressure distillation zone, the vapors and unvaporized residue separately removed from the pressure distillation zone, the vapors subjected to fractionation to condense therefrom products heavier than the desired product, the unvaporized residue delivered to a zone of reduced pressure wherein evaporation of constituents thereof is effected by the contained heat of the residue, the improvement which comprises utilizing charging oil as a cooling medium for fractionating vapors removed from the zone of pressure distillation and thereafter introducing the charging oil, prior to any cracking treatment thereof, to the unvaporized residue being delivered to the zone of reduced pressure.

16. In processes for treating high boiling point hydrocarbons to produce low boiling point productstherefrom, in which the high boiling point hydrocarbons are subjected to pressure distillation in a pressure distillation zone, the vapors and unvaporized residue separately removed from the pressure distillation zone, the vapors subjected to fractionation to condense therefrom products heavier than the desired product,

the unvaporized residue delivered to a zone of reduced pressure wherein evaporation of constituents thereof is effected by the contained heat of the residue, the improvement which comprises preheating charging oil for the process by heat extracted from vapors removed from the zone of pressure distillation, then introducing the charging oil, prior to any cracking treatment thereof, to the zone of reduced pressure in which distillation of unvaporized residue removed from the zone of pressure distillation is effected ,to volatilize from the charging oil constituents amenable to treatment in the zone of pressure distillation, subjecting the thus volatilized constituents of the charging oil to fractionation and returning the condensate derived to the zone of pressure distillation.

17. A hydrocarbon oil cracking process which comprises passing the oil in a restricted stream through a heating zone and heating the same therein to cracking temperature under pressure, dischargingr the'heated oil into a vapor separating zone and 'separating the same therein under pressure into vapors and unvaporized oil, separately removing the vapors and unvaporized oil from said separating zone, passing charging oil for the process in indirect heat exchange with hot products formed in the operation, combining charging oil 'so preheated with said unvaporized oil, partially distilling the resultant mixture under lower pressure than is maintained on said separating zone thereby vaporizing portions of the charging oil and said unvaporized oil, condensing heavier fractions ,of the vapors thus evolved, and supplying the condensed heavier Afractions to said heating zone. v

18. A hydrocarbon oil cracking process which comprises passing the oil in a restricted stream through a heating zone and heating the same therein to cracking temperature under pressure, discharging the heated oil into a vaporseparating zone and separating the saine therein under pressure into vapors. and unvaporized oil, Aseparately removing the vapors and unvaporized oil from said separating zone, dephlegmating said vapors in heat exchange with charging oil -for the process and thereby. preheating the chargingoil, combining the preheated charging oil .prior'to any cracking treatment thereof Withsaid unvaporized oil, partially distilling the resultant mixture under lower pressure than is maintained on said separating zone thereby vaporizingportions of the charging o il and said unvaporized oil, condensing heavier fractions of the vapors thus evolved, and supplying the condensed heavier fractions to said heating zone.

19. In processes for treating high boiling point hydrocarbons to produce low boiling point products therefrom, in-whch the high boiling point hydrocarbons are subjected to pressure distillation in a pressure. distillation zone, the vapors and unvaporized residue separately removed from the pressure distillation zone, the vapors subjected to fractionation to condense therefrom products heavier than the desired product; the unvaporized residue delivered to a zone'` of reduced pressure wherein evaporation of constituents thereof .is effected by the contained heatl of the residue, the improvement which comprises utilizing charging oil as a cooling medium for fractionatingvapors. removed from the zone of pressure distillation and thereafter introducing charging oil, prior to. any cracking treatment thereof, to the unvaporized residue being 'delivered to the zone-of reduced pressure. f

20. In processes for treating highboiling point hydrocarbons toproduce 1ow b.01,ing Point products therefrom, in which the high boiling point hydrocarbonsare subjected to pressure Ydistillation in a pressure distillation zone... 4:the vapors and unvaporizedl residue separately removed from the pressure ,distillation zone, the vapors subjected to fractionation to condense therefrom products ,heavierr than the desired product,.the unvaporized residuo delivered to a zone of'reducedvpressure wherein evaporation of constituents thereof is .effected by the contained heat of the. residue, the ,improvement which comprises preheating charging oil for the 2,021,471 process by heat extracted from vapors removed from the zone of pressure distillation, then introducing charging oil, prior to any cracking treatment thereof, to the zone of reduced pressure in which distillation of unvaporized residue removed from the zone of pressure distillation is eiected to volatilize from the charging oil constituents amenable to treatment in the zone of pressuredistillation, subjecting the thus volatil-k ized constituents of the charging oil to fractionavapors in heat exchange with charging oil for the process and thereby preheating the charging oil, combining preheated charging oil prior to any cracking treatment thereof with said unvaporized oil, partially distilling the resultant mixture under lower pressure than is maintained on said separating zone thereby vaporizing portions of the charging oil and said unvaporized oil, condensing heavier fractions of the vapors thus evolved, and supplying the condensed vheavier fractions to said heating zone.

22. A process for the production of gasoline and other oils from hydrocarbon oils which comprises subjecting a mass of hydrocarbon oils to a cracking temperature under pressure to crack said oils and evolve vapors therefrom, withdrawing residual oils from said mass of oils, reducing pressure on the oils so withdrawn while the latter are in a heated condition to flash a portion thereof into hot vapors, separating said vapors from unvaporized residual oils, heating additional hydrocarbon oils to effect a distillation of vapors therefrom, separating vapors so distilled from the unvaporized portion of said additional hydrocarbon oils, mixing out of contact with unvaporized oils vapors so distilled and separated with hot vapors flashed and separated from said withdrawn oils to form a composite distillate, fractionally condensing and separating out heavier fractions from said composite distillate to form a composite condensate, and introducing said composite condensate into the mass of hydrocarbon oils subjected to said cracking temperature and pressure heretofore mentioned.

23. A process for the production of gasoline and other oils from hydrocarbon oils which comprises subjecting a mass of hydrocarbon oils to a cracking temperature under pressure to crack said oils and evolvev vapors therefrom, withdrawing residual oils from said mass of oils, effecting vaporization of a portion of the residual oils so withdrawn, separating evolved vapors from unvaporized residual oils, heating additional hydrocarbon oils to eect a distillation of vapors therefrom, separating vapors so distilled from the unvaporized portion of said additional hydrocarbon oils, mixing out of contactwith unvaporized oils vapors so distilled and separated with vapors evolved and separated from said withdrawn oils to form a composite distillate, fractionally condensing and separating out heavier fractions from said composite distillate to form a composite condensate, and introducing said composite condensate into the mass of hydrocarbon oils subjected to said cracking temperature and pressure heretofore mentioned.

24. A process for the production of gasoline and other oils from hydrocarbon oils which comprises subjecting a mass of hydrocarbon oils to a cracking temperature under pressure to crack said oils and evolve vapors therefrom, separating said vapors into a vapor portion containing gasoline fractions and a reflux condensate portion, withdrawing residual oils from said mass of oils, 10 reducing pressure on the oils so withdrawn while the latter are in a heated condition to flash a portion thereof into hot vapors, separating said vapors from unvaporized residual oils, heating additional hydrocarbon oils to effect a distillation of vapors therefrom, separating vapors so distilled from the unvaporized portion of said additional hydrocarbon oils, mixing out of contact with unvaporized oils, vapors so distilled and separated with hot vapors ashed and separated from said withdrawn oils to form a composite distillate, fractionally condensing and separating out heavier fractions from said composite distillate to form a composite condensate, introducing said composite condensate into said reflux condensate portion to form a mixture of oils, and introducing the mixture of oils thus formed into the mass of hydrocarbon oils subjected to said cracking temperature and pressure heretofore mentioned.

25. A process for the production of gasoline and other oils from hydrocarbon oils which comprises Ysubjecting a mass of hydrocarbon oils to a cracking temperature under pressure to crack said oils and evolve vapors therefrom, separating said vapors into a vapor portion containing gasoline fractions and a reflux condensate portion, withdrawing residual oils from said mass of oils, eiecting vaporization of a portion of the residual oils so withdrawn, separating evolved vapors from unvaporized residual oils, heating additional hydrocarbon oils to eect a distillation of vapors therefrom, separating vapors so distilled from the unvaporized portion of said additional hydrocarbon oils, mixing out of contact with unvaporized oils vapors so distilled and separated with vapors evolved and separated from said withdrawn oils to form a composite distillate, fractionally condensing and separating out heavier fractions from said composite distillate to form a composite condensate, introducing said composite condensate into said reflux condensate portion to form al mixture of oils, and introducing the mixture of oils thus formed into,the mass of hydrocarbon oils subjected to said cracking t temperature and pressure heretofore mentioned.

26. The method of cracking hydrocarbon oils which comprises subjecting'a 'owing stream of distillate oil cracking stock to cracking under high superatmospheric pressure, discharging the stream of cracked products into an enlarged separating zone maintained under superatmospheric pressure wherein vapors and liquid residual products separate, separately withdrawing the resulting vaporsI fractionating them to condense as reflux condensate heavier constituents thereof, separately withdrawing liquid residual products from said separating zone and discharging them into a distilling zone maintained under a materially reduced pressure -wherein further vaporization of 70 said residual products is effected, passing relatively cool charging oil in indirect heat exchange with hot cracked products formed in the operation to heat said charging oil to a temperature suiiicient to vaporize lower boiling components z5 thereof, separating the vaporized constituents of said charging oil, thereafter introducing the preheated unvaporized fresh oil into said low pressure distilling zone at a point above the point of introduction of said residual products thereinto whereby said preheated fresh oil undergoes distillation in intimate contact with vapors evolved from said residual products, fractionating the resulting mixture of vapors from said low pressure distilling zone in admixture with vaporized constituents separated from said charging oil to form a clean condensate stock, subjecting a flowing stream of condensate formed during said lastnamed fractionation to cracking under high superatmospheric pressure and discharging the resulting cracked products into said enlarged separating chamber.

27. The process of treating hydrocarbon oil which comprises passing relatively clean cracking stock through a cracking zone wherein it is raised to a cracking temperature and subjected to conversion, introducing the resulting cracked products into a distilling zone wherein lighter products separate as vapors from the heavier liquid residues, passing fresh relatively heavy charging stock in indirect heat exchange relation with light products so separated whereby said charging stock is heated to a distilling temperature, introducing the preheated charging stock into a strippingv zone wherein lighter constituents thereof separate as vaporsleaving liquid reduced crude, passing resulting reduced crude in indirect heat exchange with heavier liquid products separated in the distilling zone and introducing the further heated reduced crude into said distilling zone in countercurrent now with the vapors rising therethrough, fractionating the vapors from said distilling zone, condensing and collecting the uncondensed vapors resulting from said last-named fractionation and withdrawing unvaporized residual products from said distilling zone.

28. The process in accordance with claim 27 which further comprises passing reflux condensate formed in the fractionating zone t6 the cracking zone as clean relatively heavy cracking stock therefor.

29. The process in accordance with claim 27 which further comprises removing the light vapors from said stripping zone and introducing said vapors into .the fractionating zone for fractionation therein.

30. In the process for producing lower boiling hydrocarbon products from higher boiling hydrocarbons wherein the higher boiling hydrocarbons are subjected to conversion conditions and the conversion products separated into vapors and unvaporized residuum; the improvement which comprises introducing vapors formed during the conversion treatment into a distilling zone, introducing unvaporized residuum from the con version treatment into said zone above the introduction of said vapors and at a temperature below that of said vapors, introducing charging oil for the process into said zone above the introduction of unvaporized residuum whereby the hot vapors iiow countercurrent to the unvaporized residuum and the fresh charging oil, fractionating the vapors from said distilling zone, collecting and removing a clean condensate resulting from said fractionation, subjecting said condensate to conversion treatment, withdrawing residuum from said distilling zone, preheating said fresh charging oil by indirect heat exchange with said last-named residuum and condensing and collecting uncondensed vapors from said fractionation as a final distillate product.

31. The process of treating hydrocarbon oil which comprises passing relatively clean cracking stock through a cracking zone wherein it 5 ing stock into a stripping zone wherein lighter 15 constituents thereof separate as vapors leaving liquid reduced crude, passing the reduced crude into said distilling zone in countercurrent iiow with vapors rising therethrough, combining vapors from said stripping zone with the vapors 2K0v from said distilling zone, fractionating the combined vapors to condense heavier constituents thereof, condensing and collecting uncondensed vapors from said last-named fractionation as the desired distillate product and withdrawing un- 25 vaporized residual products from said distilling zone.

l 32. In a process for converting higher boiling hydrocarbons into lower boiling hydrocarbons suitable for motor fuel wherein a relatively clean 30 cracking stock is passed through a cracking zone and subjected to conversion therein, the resulting converted products then introduced into a separating zone for separating lighter vapor products from heavier liquid residuum; the im- 35 provement which comprises passing the liquid residuum into a zone maintained at a pressure below that existing in said separating zone to effect further vaporization of said liquid residuum by the contained heat thereof. passing fresh charging oil in direct counterflow contact with vapor products from said separating zone to vaporize lighter constituents thereof, commingling the vapors resulting from distillation of said fresh oil and the vapors from the distil- 452 hydrocarbon products wherein the higher boiling hydrocarbons are subjected to conversion conditions, the conversion products separated inlto vapors and unvaporized residuum, the vapors subjected to fractionation and the uncondensed 60 vapors from said fractionation condensed and collected as a final distillateproduct; the improvement which comprises passing the unvaporized residuum into a vertically elongated distnling chamber provided with a. plurality of 65 vertically spaced baiiies and maintained under reduced pressure wherein further vaporization is eifected'by the contained heat of the residuum, passing charging oil in indirect heat exchange with hot products formed in the operation, pass- 70 ing charging oil so preheated into the reduced pressure distilling chamber above the introduction of said unvaporized residuum and above the lowermost baille therein whereby said charging oil flows countercurrent to the upflow of 15 vapors therein and serves as a reiiuxing medium for the vapors liberated from .said residuum in the reduced pressure chamber and whereby the lighter components of the charging stock are vaporized, fractionating the vapors from the reduced pressure zone to form a condensate and subjecting condensate formed during said fractionation to the first-mentioned conversion treatment.

34. A process for converting hydrocarbon oil which comprises subjecting oil to cracking conditions in a heating zone, passing the products from the heating zone into an enlarged chamber wherein the products separate into vapors and unvaporized residue, withdrawing residue from the enlarged chamber and subjecting it to distillation in a zone of reduced pressure with the formation of further vapors and residue, condensing heavier constituents of the iirst and last named vapors, separating a portion of condensate so formed containing constituents of said last named vapors and commingling the same without prior heating to cracking temperature with heated oil from the heating zone prior to its entrance into the enlarged chamber to cool said heated oil.

35. In the hydrocarbon oil cracking process wherein the oil is heated to cracking temperature under pressure while passing in al restricted stream through a heating zone, the heated oil thence discharged into a reaction zone, from which vapors and unvaporized oil are separately withdrawn, and the unvaporized oil flash-distilled by pressure reduction with the formation of flashed vapors; the improvement which comprises fractionating the flashed vapors thereby forming a reflux condensate, introducing at least a portion of the reiiuxed condensate, without prior heating to cracking temperature into the heated oil discharging from the heating zone to thereby cool said heated oil, fractionating the vapors removed from the reaction zone and returning a portion of the reflux condensate separated therefrom to the heating zone for further treatment therein.

36. A process for the production of gasoline and other oils from hydrocarbon oils which comprises subjecting a stream of hydrocarbon oil to cracking temperature under pressure to crack said oil, passing the stream of cracked products into an enlarged separating zone wherein vapors and residual liquid products separate, withdrawing residual oils from said separating zone and passing them to a distilling zone maintained under reduced pressure to ash a portion thereof into vapors, separately withdrawing vapors from said reduced pressuredistilling zone, heating and distilling additional hydrocarbon oils in a separate distilling zone to effect a distillation oi vapors therefrom, separately withdrawing vapors from said separate'distilling zone, mixing vapors withdrawn from said distilling zones, fractionally condensing and separating out heavier fractions from the resulting vapor mixture to form a condensate, withdrawing condensate from said frac- 15 tionating operation and supplying said condensate, in'the absence of residual constituents of the oils treated in said separate distilling zones to the aforesaid cracking operation as said stream of hydrocarbon oil. 37. A process for the production of gasoline and other oils from hydrocarbon oils which comprises subjecting a stream of hydrocarbon oil to cracking temperature under pressure to crack said oil, passing the stream of cracked products 25 into an enlarged separating zone wherein vapors and residual liquid products separate, separating said vapors into a vapor portion containing gasoline fractions and a reflux condensate portion, withdrawing residual oils from said separating zone and passing them to a distilling zone maintained under reduced pressure to flash a portion thereof into vapors, separately withdrawing vapors from said reduced pressure distilling zone, heating and distilling additional hydrocarbon oils in a separate distilling zone to eiect a distillation of vapors therefrom, separately withdrawing vapors from said separate distilling zone, mixing vapors withdrawn from said distilling zones, fractionally condensing and separating out heavier fractions from the resulting vapor mixture to form a condensate, withdrawing condensate from said fractionating operation and supplying said condensate, in the absence of residual constituents of the oils treated in said separate distilling zones, together with said reflux condensate separated from the vapors from said enlarged separating zones to the aforesaid cracking operation as said stream of hydrocarbon oil.

ROBERT E. WILSON.

CERTIFICATE CE CORRECTION.

Patent No.' 2,021,471. November 19, 1955.

ROBERT E. WILSON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring Correction as follows: Page 2, second column. line 32, after the syllable "ample" insert a comma; page 5, first column, line l5, after the numeral "ll" second occurrence, insert a comma; and second Column, line 6, for' "506F. read 550F. and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of January, A. D. 1936.

Leslie Frazer (Sea-1) Acting Commissioner of Patents. 

